A classified U.S. Senate report found that the CIA's legal justification for the use of harsh interrogation techniques that critics say amount to torture was based on faulty legal reasoning, McClatchy news service reported on Thursday.

The Central Intelligence Agency also issued erroneous claims about how many people it subjected to techniques such as simulated drowning, or "water boarding," according to the news service, citing conclusions from the Senate Select Committee on Intelligence report obtained by McClatchy.

The report also concluded that the CIA used interrogation methods that were not approved by its own headquarters or the U.S. Justice Department, impeded White House oversight and actively evaded oversight both by Congress and its own Inspector General.

The CIA also provided false information to the U.S. Justice Department, which used that information to conclude that the methods would not break the law because those applying them did not specifically intend to inflict severe pain or suffering, the report added.